<template>
  <div>
    <el-switch
      v-model="draggable"
      active-text="开启拖拽"
      inactive-text="关闭拖拽"
    ></el-switch>
    <el-button v-if="draggable" @click="batchSave">批量保存</el-button>
    <el-button type="danger" @click="batchDelete">批量删除</el-button>
    <el-tree
      :data="menus"
      :props="defaultProps"
      :expand-on-click-node="false"
      show-checkbox
      node-key="catId"
      :default-expanded-keys="expandedKey"
      :draggable="draggable"
      :allow-drop="allowDrop"
      @node-drop="handleDrop"
      ref="menuTree"
    >
      <span class="custom-tree-node" slot-scope="{ node, data }">
        <span>{{ node.label }}</span>
        <span>
          <el-button
            v-if="node.level <= 2"
            type="text"
            size="mini"
            @click="() => append(data)"
            >Append</el-button
          >
          <el-button type="text" size="mini" @click="edit(data)"
            >Edit</el-button
          >
          <el-button
            v-if="node.childNodes.length == 0"
            type="text"
            size="mini"
            @click="() => remove(node, data)"
            >Delete</el-button
          >
        </span>
      </span>
    </el-tree>

    <el-dialog
      :title="title"
      :visible.sync="dialogVisible"
      width="30%"
      :close-on-click-modal="false"
    >
      <el-form :model="category">
        <el-form-item label="分类名称">
          <el-input v-model="category.name" autocomplete="off"></el-input>
        </el-form-item>
        <el-form-item label="图标">
          <el-input v-model="category.icon" autocomplete="off"></el-input>
        </el-form-item>
        <el-form-item label="计量单位">
          <el-input
            v-model="category.productUnit"
            autocomplete="off"
          ></el-input>
        </el-form-item>
      </el-form>
      <span slot="footer" class="dialog-footer">
        <el-button @click="dialogVisible = false">取 消</el-button>
        <el-button type="primary" @click="submitData">确 定</el-button>
      </span>
    </el-dialog>
  </div>
</template>

<script>
import Vue from "vue";
//这里可以导入其他文件(比如: 组件，工具js, 第三方插件js, json文件, 图片文件等等)
//例如: import 《组件名称》 from '《组件路径》';

export default {
  //import引入的组件需要注入到对象中才能使用
  components: {},
  props: {},
  data() {
    return {
      pCids: [], // 用于存放每次拖拽后的节点的父节点id
      draggable: false, // 默认设为false，关闭拖拽
      updateNodes: [],
      maxLevel: 0, // 树结构最大层级：0
      title: "",
      dialogType: "", // edit/add
      category: {
        name: "",
        parentCid: 0,
        catLevel: 0,
        showStatus: 1,
        sort: 0,
        icon: "",
        productUnit: "",
        catId: null,
      },
      dialogVisible: false,
      menus: [],
      expandedKey: [],
      defaultProps: {
        children: "children",
        label: "name",
      },
    };
  },
  //计算属性 类似于data概念
  computed: {},
  //监控data中的数据变化
  watch: {},
  //方法集合
  methods: {
    // 引入:expand-on-click-node="false"，取消单击函数
    // handleNodeClick(data) {
    //   console.log(data);
    // },

    getMenus() {
      this.$http({
        url: this.$http.adornUrl("/product/category/list/tree"),
        method: "get",
      }).then(({ data }) => {
        console.log("成功获取到菜单数据...", data.data);
        this.menus = data.data;
      });
    },

    // 增加
    append(data) {
      console.log("append", data);
      this.dialogType = "add";
      this.title = "添加分类";
      this.dialogVisible = true;
      this.category.parentCid = data.catId;
      this.category.catLevel = data.catLevel * 1 + 1;

      this.category.catId = null;
      this.category.name = null;
      this.category.icon = "";
      this.category.productUnit = "";
      this.category.showStatus = 1;
      this.category.sort = 0;
    },

    // 修改
    edit(data) {
      console.log("要修改的数据", data);
      this.dialogType = "edit";
      this.title = "修改分类";
      this.dialogVisible = true;

      // 发送请求获取当前节点最新的数据
      this.$http({
        url: this.$http.adornUrl(`/product/category/info/${data.catId}`),
        method: "get",
      }).then(({ data }) => {
        // 请求成功
        console.log("要回显的数据", data);
        this.category.name = data.data.name;
        this.category.catId = data.data.catId;
        this.category.icon = data.data.icon;
        this.category.productUnit = data.data.productUnit;
        this.category.parentCid = data.data.parentCid;

        this.category.catLevel = data.data.catLevel;
        this.category.showStatus = data.data.showStatus;
        this.category.sort = data.data.sort;
        /**
         * 修改--只想修改部分数据时（产品名，产品icon，产品件数）--传递参数时；两种方式
         * 1、只传递需要修改的参数信息--因此只需要回显需要修改参数信息；并将需要的参数封装成一个对象传递
         * data: this.$http.adornData({ catId, name, icon, productUnit }, false),
         * 2、全部传递---需要回显不需要的参数信息（catLevel: 0, showStatus: 1, sort: 0,）
         * this.category.catLevel = data.data.catLevel;
         * this.category.showStatus = data.data.showStatus;
         * this.category.sort = data.data.sort;
         * data: this.$http.adornData(this.category, false),
         */
      });
    },

    // 删除
    remove(node, data) {
      var ids = [data.catId];
      // 消息提示框
      this.$confirm(`是否删除【${data.name}】菜单？`, "提示", {
        confirmButtonText: "确定",
        cancelButtonText: "取消",
        type: "warning",
      })
        .then(() => {
          // POST请求
          this.$http({
            url: this.$http.adornUrl("/product/category/delete"),
            method: "post",
            data: this.$http.adornData(ids, false),
          }).then(({ data }) => {
            this.$message({
              message: "菜单删除成功",
              type: "success",
            });
            // 刷新出新的菜单
            this.getMenus();
            // 设置需要默认展开的菜单
            this.expandedKey = [node.parent.data.catId];
          });
        })
        .catch(() => {});
      console.log("remove", node, data);
    },

    // 弹窗--添加三级分类
    addCategory() {
      console.log("提交的三级分类数据", this.category);
      this.$http({
        url: this.$http.adornUrl("/product/category/save"),
        method: "post",
        data: this.$http.adornData(this.category, false),
      }).then(({ data }) => {
        this.$message({
          message: "菜单保存成功",
          type: "success",
        });
        // 关闭对话框
        this.dialogVisible = false;
        // 刷新出新的菜单
        this.getMenus();
        // 设置需要默认展开的菜单
        this.expandedKey = [this.category.parentCid];
        console.log("addCategory", data);
      });
    },

    // 修改三级分类数据
    editCategory() {
      var { catId, name, icon, productUnit } = this.category;
      //var data = {catId: catId, name: name, icon: icon, productUnit: productUnit};
      //var data = {catId, name, icon, productUnit};
      this.$http({
        url: this.$http.adornUrl("/product/category/update"),
        method: "post",
        data: this.$http.adornData({ catId, name, icon, productUnit }, false),
      }).then(({ data }) => {
        this.$message({
          message: "菜单修改成功",
          type: "success",
        });
        // 关闭对话框
        this.dialogVisible = false;
        // 刷新出新的菜单
        this.getMenus();
        // 设置需要默认展开的菜单
        this.expandedKey = [this.category.parentCid];
      });
    },

    // 弹窗确认函数--新增/修改
    submitData() {
      if (this.dialogType == "add") {
        this.addCategory();
      }
      if (this.dialogType == "edit") {
        this.editCategory();
      }
    },

    // 拖拽时判定目标节点能否被放置
    // draggingNode:被拖拽的节点
    // dropNode:被拖拽到哪个节点
    // type:位置
    allowDrop(draggingNode, dropNode, type) {
      // 1、被拖动的当前节点以及所在的父节点总层数不能大于3

      // 1)、被拖到的当前节点总层数
      console.log("allowDrop:", draggingNode, dropNode, type);

      // 计算当前节点总层数
      this.countNodeLevel(draggingNode);

      // 当前正在拖到的节点+父节点所在的深度不大于3即可
      console.log("深度this.maxLevel：", this.maxLevel);
      let deep = Math.abs(this.maxLevel - draggingNode.level) + 1;
      console.log("深度deep：", deep);

      // this.maxLevel
      if (type == "inner") {
        /*console.log(
          `this.maxLevel: ${this.maxLevel}; draggingNode.data.catLevel: ${draggingNode.data.catLevel}; dropNode.level: ${dropNode.level}`
        );*/
        return deep + dropNode.level <= 3;
      } else {
        return deep + dropNode.parent.level <= 3;
      }
    },

    // 计算当前节点总层数
    countNodeLevel(node) {
      // 找到所有子节点，求最大深度
      if (node.childNodes != null && node.childNodes.length > 0) {
        for (let i = 0; i < node.childNodes.length; i++) {
          if (node.childNodes[i].level > this.maxLevel) {
            this.maxLevel = node.childNodes[i].level;
          }
          this.countNodeLevel(node.childNodes[i]);
        }
      }
    },

    // 拖拉成功事件函数
    handleDrop(draggingNode, dropNode, dropType, ev) {
      console.log("handleDrop: ", draggingNode, dropNode, dropType);
      // 1、当前节点最新的父节点id
      let pCid = 0;
      let siblings = null;

      if (dropType == "before" || dropType == "after") {
        pCid =
          dropNode.parent.data.catId == undefined
            ? 0
            : dropNode.parent.data.catId;
        siblings = dropNode.parent.childNodes;
      } else {
        pCid = dropNode.data.catId;
        siblings = dropNode.childNodes;
      }
      this.pCids.push(pCid);
      // 2、当前拖拽节点的最新顺序
      /*if (dropType == "inner") {
        siblings = dropNode.childNodes;
      } else {
        siblings = dropNode.parent.childNodes;
      }*/
      for (let i = 0; i < siblings.length; i++) {
        if (siblings[i].data.catId == draggingNode.data.catId) {
          // 如果遍历的是当前正在拖拽的节点
          let catLevel = draggingNode.level;
          if (siblings[i].level != draggingNode.level) {
            // 当前节点的层级发生变化
            /*if (dropType == "before" || dropType == "after") {
                    catLevel = dropNode.level
                } else {
                    catLevel = dropNode.level + 1;
                } */
            catLevel = siblings[i].level;
            // 修改它子节点层级
            this.updateChildNodeLevel(siblings[i]);
          }
          this.updateNodes.push({
            catId: siblings[i].data.catId,
            sort: i,
            parentCid: pCid,
            catLevel: catLevel,
          });
        } else {
          this.updateNodes.push({ catId: siblings[i].data.catId, sort: i });
        }
      }
      // 3、当前拖拽节点的最新层级
      console.log("updateNodes:", this.updateNodes);
      /* // 将请求放到 批量保存 按钮中
      this.$http({
        url: this.$http.adornUrl("/product/category/update/sort"),
        method: "post",
        data: this.$http.adornData(this.updateNodes, false),
      }).then(({ data }) => {
        this.$message({
          message: "菜单顺序修改成功",
          type: "success",
        });
        // 刷新出新的菜单
        this.getMenus();
        // 设置需要默认展开的菜单
        this.expandedKey = [pCid];
        // 拖拽成功，将updateNode和maxLevel设置成默认值
        this.updateNodes = [];
        this.maxLevel = 0;
      });*/
    },

    // 修改它子节点层级
    updateChildNodeLevel(node) {
      if (node.childNodes.length > 0) {
        for (let i = 0; i < node.childNodes.length; i++) {
          var cNode = node.childNodes[i].data;
          this.updateNodes.push({
            catId: cNode.catId,
            catLevel: node.childNodes[i].level,
          });
          this.updateChildNodeLevel(node.childNodes[i]);
        }
      }
    },

    // batchSave：批量保存：用于树形菜单拖拽后，进行批量保存，降低与数据库进行交互
    batchSave() {
      this.$http({
        url: this.$http.adornUrl("/product/category/update/sort"),
        method: "post",
        data: this.$http.adornData(this.updateNodes, false),
      }).then(({ data }) => {
        this.$message({
          message: "菜单顺序修改成功",
          type: "success",
        });
        // 刷新出新的菜单
        this.getMenus();
        // 设置需要默认展开的菜单
        this.expandedKey = this.pCids;
        // 拖拽成功，将updateNode和maxLevel设置成默认值
        this.updateNodes = [];
        this.maxLevel = 0;
        this.pCids = [];
      });
    },

    // 批量删除
    batchDelete() {
        let catIds = []; // 用于存放批量删除catId
        let checkedNodes = this.$refs.menuTree.getCheckedNodes();
        console.log("被选中的元素", checkedNodes);
        for (let i = 0; i < checkedNodes.length; i++) {
            catIds.push(checkedNodes[i].catId);
        }
        
        // 消息提示框
        this.$confirm(`是否批量删除【${catIds}】菜单？`, "提示", {
        confirmButtonText: "确定",
        cancelButtonText: "取消",
        type: "warning",
      })
        .then(() => {
          // POST请求
          this.$http({
            url: this.$http.adornUrl("/product/category/delete"),
            method: "post",
            data: this.$http.adornData(catIds, false),
          }).then(({ data }) => {
            this.$message({
              message: "菜单批量删除成功",
              type: "success",
            });
            // 刷新出新的菜单
            this.getMenus();
          });
        })
        .catch(() => {});
    },
  },

  //生命周期 - 创建完成(可以访问当前this实例)
  created() {
    this.getMenus();
  },

  //生命周期 - 挂载完成(可以访问DOM元素)
  mounted() {},

  beforeCreate() {}, //生命周期 - 创建之前

  beforeMount() {}, //生命周期 - 挂载之前

  beforeUpdate() {}, //生命周期 - 更新之前

  updated() {}, //生命周期 - 更新之后

  beforeDestroy() {}, //生命周期 - 销毁之前

  destroyed() {}, //生命周期 - 销毁完成

  activated() {}, //如果页面有keep-alive缓存功能, 这个函数会触发
};
</script>

<style scoped>
</style>